Method and mechanism for producing gears



Aug. 7, 1928.

H. E. 'STONEBRAKER IE'IHOD AND IECHANISI FOR PRODUCING GEAR-S Filed llay 1925 Patented Aug. -7,

UNITED STATE HAROLD E. STONEBRAKER, or aocHEsTER, NEW YORK, AssIGNoa r'o G'L'EASON S. HTPATENT. OFFICE.

WORKS, OF ROCHESTER, NEW YORK, A CORPORATION NEW YORK.

METHOD AND MECHANISM r03 PRODUCING GEARS.

Application filed May :8,

single face at a time,

practiced.

A further object enable cutting both of; the invention is to a gear and pinion by a simultaneous operation on two faces, thus greatly increasing the speed of production and correspondingly reducing the cost of gear cut-ting.

Another object is to bring about such an increased cutting speed without lessening the accuracy or efliciency of the gears produced.

Still a further is to afford a method and mechanism tooth gear and pinion will producing curved mating faces of a formed on curves gradual engagement purpose of the invention for gears so that the be that insure a smooth, with a minimum of backlash resulting in extremely quietrunning gears.

An additional, p method curved tooth gears and mechanism urpose is to afford a for producing such that. any one-of a group of gears can be indiscriminately matched with any one of a group of pinions, thus greatly reducing the present day cost of gear production of matching, in pairs, sating. or conjugate errors,

ears having. excessive errors.

.With these ends embraces will appear. clearl scription, when read in conjunction withdrawing, the novel:fea-

the accompanying due to the practice gears having-compenin view, the invention the process andmechanism that from. the following deturesbeing pointed out 1n the claims following the specification.

In the. drawing:

Figure l is a View in ing a cutter mechan ism constructed according to one embodiment of the invention, with one possible position of a gearblank indicated in dotted Figure 2 is a sectional view of thecutter mechanism Figure 3 is a sectional view on line 3-3 of Figure 2;

Figure view showing the lines 4 is an enlarged detail sectional position of inner and outer toolsin a tooth spaceof a blank, and

as is now generally or refinishing the side elevation show- 1925. Serial N .2a,s49.

and generating machines, and is particularly adaptable-to gear cutting machinery of the general type employing a rotary an-,

nular face mill cutter, and such as illustrated I in Patents No. 1,325,784, December 23, 1919,

and No. 1,203,608, November -7, 1916.-

In general, the invention consists in forming two adjacent faces on afgear so .as to conform to two eccentrically related circles having radii of slightly different lengths, and this may be conveniently carried out in the mechanism shown, which includes an inner cutter. head 1 mounted on the spindle 2 and carrying an inner set of tools 3, preferably arranged circularly. 4 is an outer cutter head surrounding the inner cutter head and carrying the outer set of tools .5, preferably arranged circularly.

The two cutter heads may be arranged and driven .in a variety of ways, this being simply a matter of mechanical design, and as an exemplary practical arrangement, I have shown the outer cutterhead Aturning within a fixed'bearing 6, and operated from the inner cutter head lz'through the instrumentality of gear teeth 7 carried by the inner cutter head and engaging gear teeth '8 carried by the outer cutterhead.

' The inner cutter head 1 rotates about the center. a, while the outer cutter head 4 rotates about the center I), said centers being slightly spaced from eachother, as shown in Figures 1 and 5. Cutter head 1 is arranged within cutterhead 4, so that the two sets'of tools move in curved paths on arcs of eccentric circles having radii of slightly different lengths. y I j A bevel gear blank is shown in opera-' tive relation to the cutter mechanism at a1: in Figure 1', The bevel gear blank is shown it is to be following claims.

arranged at the upper side of the cutter mechanism where the circles in which the two sets of tools travel are closest together. By positioning the blank with reference to the cutter mechanism so that the two sets of tools cut closest together at one side of the gear face and farthest apart at the opposite,

side of the gear face, tapering or converging grooves and teeth are produced. This is advantageous in the case of bevel gears where either the teeth or grooves must taper, and where the best results are had by tapering both the teeth and grooves. In the case of spur gears, or where it is desirable to cut widest at the center and narrower at the sides of thegear face, the blank may be arranged at the bottom of the cutter mechanism with reference to Figure 1, so that the circles in which the tools travel are farthest apart at thecenter of the gear face, and converge toward the sides, thus affording a symmetrical convergence from the center toward the sides of the gear face. It is obviously within the province of the invention to position the gear blank, or the portion of the blank being cut, at any desired point with reference to the circular paths of the twos ets of tools, depending upon the amount of convergence or form of groove or tooth that is desired between the two faces being out.

v In the illustrated arrangement, the'outer tools 5 travelling about center 6 form the concave face of the groove shown in Figure 5, and the inner tools 8 travelling about center a form the convex face of the groove. If the inner and outer sets of tools engage opposite sides of a tooth instead of a space or groove, the inner tools 3 would form the concave side of a tooth and the outer tools 5 would form the convex side of the tooth. The same cutter mechanism can be used to out both a gear and pinion of a pair, in

which event thc concave faces-on the pinion will contact with or mate with the convex faces on the gear and vice versa. Thus the mating or contacting faces of the two members of a pair correspond to the two faces shown in Figure 5, and conform to circles on slightly different radii and about different centers.

. .lVhere the term cutting orcutter is used throughout this specification and claims, understood as comprehending also a grinding or abradingimethod or mechanism as well as the specific system or apparatus shown herein. The invent-ion may be carried out with other arrangements and mechanism than that disclosed, and this ap plication is intendedto cover any modifica- .tions or departures embodying the principles set forth or coming within the scope of the The application of the cutter mechanism described herein to any lmown or conventional gear cutting or genconformity circles.

cylindrical and tapered crating machinery is easily within the skill of those mechanically versed in the art of gear manufacture.

I claim: p

l. The method of producing curved tooth cylindrical and tapered gears consisting in simultaneously forming .two adjacent faces by rotating independent cutters about d fferent centers so as to move their tools in to two eccentrically related 2. The m'ethod of producing curved tooth cylindrical and tapered gears cons sting in forming two ad acent faces icy-simultane- 'ously moving two tools about different centers in curved the other. e

3. A gear cutter mechanism for producing gears comprising a plurality of independentlysupported tools movable in curved paths across the face of a gear blank in'cutting relation with adjacent tooth faces, and means for simultaneously imparting movement to said tools.

4'. The method of producing curved tooth cylindrical and tapered gears consisting in simultaneously cutting two adjacent spacepaths disposed one within forming faces by moving two sets of tools through a single tooth space in circular paths which are eccentrically related and have radii of different lengths.

5. A gear cutter mechanism for producing cylindrical and tapered gears comprising a plurality of independentlysupported tools which are so related as to be movable simultaneously in curved paths across the face of a gear blankthrough a single tooth space and in cutting relation with the adjacent bounding faces of such tooth space, and

means for imparting simultaneous movement to sa d tools.

6. A gear cutter mechanism for producing.

cylindrical and conical gears comprising two cutter heads carrying sets of'tools adapted circles located one to travel in eccentric within the other, means for rotating one of said cutter heads, and a direct gear connection between the two cutter. heads.

7. The method of producing curved tooth cylindrical and conical gears consisting in simultaneously cutting two adjacent tooth faces by moving two'tools about different centers in separate curved paths across the face of a gear blank.

8. A mechanism for cutting cylindrical and tapered gears comprising two cutter heads carrying sets of tools adapted to travel in eccentric circles located one within the other and to cut adjacent space bounding faces simultaneously, the tools on one cutter head being located between adjacent tools on V the other cutter head, and means for simultaneously impartingmovement to the cutter heads.

9. Themethod of producing curved tooth cylindrical and tapered gears, consisting in curved paths about different centers across 10 I simultaneouslycutting tWo adjacent space the face of a gear blank in cutting relation forming faces by moving two sets of tools with the space-forming I faces of a single through a single tooth space in circular paths tooth space, and means for simultaneously Which are eccentrically related and have imparting move ent to aid tools,

radii of different lengths. In Witness whereof, I have hereunto signed 15 10. A gear cutter mechanism for producmy name.

ing cylindrical and tapered gears comprising" a plurality of series of tools movable in HAROLD E. STONEBRAKER. 

